Snow vehicles

ABSTRACT

A POWERED SNOWVEHICLE IN WHICH A FRAME PORTION UPON WHICH PASSENGERS ARE SEATED AND A FRONT SKI ARE TILTABLE WITH RESPECT TO REAR, SNOW ENGAGING TRACKS, OR SKIS, AND WITH RESPECT TO TERRAIN.   D R A W I N G

mted States Patent 1191 [111 3,7 7 9,32

Trautwein cc. 18, 1973 SNOW VEHICLES 3,504,752 4/1970 Milward 180/5 R[76] Inventor: Wolfgang Trautwein, 3529 Carroll 311338 2: 12:31: CircleHunts/111e, 30331 3,583,507 6/1971 Trautweinn 180 5 R [22] Filed: Oct.4, 1971 Primary ExaminerLeo Friaglia [21] Appl' l86026 AssistantExaminer-Vincent Hom Attorney-C. A. Phillips [52] US. Cl. 180/5 R, 180/3[51] Int. 862m 57 ABSTRACT [58] Field of Search 180/3, 5 R, 16

A powered snow vehicle in wh1ch a frame portion upon [56] ReferencesCited wiiich passengers are seated and a front ski are tiltable UNITEDSTATES PATENTS wlth respect to rear, snow engaging tracks, or skis, and

with respect to terrain. 2,749,189 6/1958 France 180/5 R 3,023,8243/1962 Bombardier 180/5 R 7 Claims, 5 Drawing Figures SNOW VEHICLESBACKGROUND OF THE IN INVENTION This invention relates to powered snowvehicles popularly referred to as snowmobiles.

GENERAL DESCRIPTION OF THE PRIOR ART Heretofore snowmobiles (snowvehicles) have lacked maneuverability because of the difficulty, orinability, to shift loading to one side, or banking, when making a turn.In Applicants U.S. Pat. No. 3,583,507 the problem is overcome withrespect to certain vehicles wherein a pair of spaced skis areinterconnected to the main body of the snowmobile by means of aparallelogram.

SUMMARY OF THE INVENTION It is an object of this invention to provide animproved snowmobile wherein banking is enabled with out the necessity ofconnecting outboard skis by means of a parallelogram and which skistilted asthe vehicle was banked.

It is another object of this invention to provide a snowmobile that issimpler and of less expensive construction.

In accordance with the invention a snowmobile is constructed of threeprincipal assemblies, a body member for supporting at least one rider, arear snow engaging assembly consisting of a propulsion unit and widelyspaced lateral support, and a front snow engaging assembly typically inthe form of a ski attached through steering means to the main bodymember. The main body member is mounted to the rear snow engagingassembly to permit pivotal movement about an axis generally parallel tothe longitudinal axis of the snowmobile. A reference platform in theform of foot supports is attached on opposite sides of the rear snowengaging assembly to enable the rider to apply a differential forcebetween the main body member and the rear snow engaging assembly toachieve banking or other desired attitudes with respect to terrain andindependent of the slopeof the terrain.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fullyunderstood by the following description when taken together with thedrawings in which:

FIG. 1 is a front view of a snow vehicle constructed in accordance withApplicants invention.

FIG. 2 is a rear view of a snow vehicle as shown in FIG. 1 except thatdrive of the snow vehicle is by means of a single track rather than twotracks as shown in FIG. 1.

FIG. 3 is a side elevation of the snow vehicle.

FIG. 4 is a detail of the front pivotal suspension of the main body ofthe snow vehicle.

FIG. 5 is a front view of an alternate embodiment of a vehicle ascontemplated by Applicants invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, andparticularly to FIGS. 1, 3, and 4, snowmobile consists basically of anelongated main frame assembly 12, rear drive unit 14 and front supportski 16 having essentially planar bottom surface 17. Rear drive unit 14includes spaced tracks 18 having essentially planar but grooved bottomsurfaces 19, driven by a conventional engine 20 and provided with upperplatform 21 which is equipped with spaced longitudinal ridges 22,configured to provide foot rests for the rider. Engine 20 drives tracks18 through a front sprocket assembly 20a (not shown in detail) andtracks 18 are supported at the rear by rear sprocket assembly 20b (notshown in detail). An even distribution of loading on tracks 16 isachieved through suspension members 18a which are mounted on and springbiased with respect to frame assembly 12 to provide a downward forceupon tracks 18.

Snowmobile 23 shown in FIG. 2 differs only in that a single drive track24 of sufficient width for stability is employed rather than two smallerwidth spaced tracks. In each instance the front support, ski 16 asshown, would be an elongated member which would have a side edge to sideedge width of substantially less than the side edge to side edge widthof the rear support.

Main frame 12 is supported near rear end 25 by coil spring suspensionand damper assembly 26, having inner spring retaining and damper members28 and 30 which are slidably engaged, and the upper member 28 which isattached to main frame 12 by clevis arrangement 32. Lower member 30 iscoupled in a like manner to rear mounting bracket 34 by clevis assembly36. Rear mounting bracket 34 is pivotally supported by threaded stud 37,axially aligned with a like stud 38 at front end 40 of drive unit 14 andcentrally secured to rear cross member 42.

Main frame 112 extends forward and is spaced above drive unit 14providing a substantially flat upper area 44 to which multiple passengerseat 46 is attached. At a point 48 near front end 40 of drive unit 14,main frame 12 is configured upwardly to provide clearance space 50between lower surface 52 of frame 12 and drive unit 14. At point 78,further forward, frame 12 is formed into downward projecting tubularsupport member 54 having inner surface 56 dimensioned to slidably engagetubular steering column 58, the lower end 60 of which is securelyattached to cylindrical portion 62 of front mounting bracket 64.Downward projecting portion 66 of mounting bracket 64 is adapted toaccept shock absorbing insert 68 provided with inner bearing '70pivotally supported by threaded stud 38. Threaded stud 38 is attached tolower front portion 74 of motor housing 76 and is in axial alignmentwith rear supporting stud 37.

The front end 78 of main frame 12 is suspended by coil spring 80,retained by lower portion 82 of steering column 58. The upper end 86 isconfigured to contact lower surface 88 of tubular support member 54, andlower end 90 is supported by upper surface 92 of mounting bracket 64.Steering assembly 94 includes steering rod 96 joumaled within steeringcolumn 58 and fitted with handle bars 98 at upper end 100. Lower end 102of steering rod 96 is coupled to mounting shoe 104 having enlarged uppersupport collar M6. The latter is provided with a lower flared portion108 attached to flexible mount 110, by U shaped clamp 112. Front portionll 14 of flexible mount 1 10 is secured to steering ski 16 by mountingsocket 116 and is held firmly in place by threaded cap screws 1116 nearrear end 120.

Flexible flared portion 108 prevents ski 16 from tipping excessivelywhile yet allowing ski 116 to follow contour of the terrain. Locking pin122 is inserted through an opening 124 in main frame 12 at anappropriate point 126 in front of seat 46. It is provided with knob 127so that, while restrained by a friction device, not shown, it may bepushed inward to engage socket 128 provided in upper portion 130 ofdrive unit 14, thus locking main frame 12 in a stable lateral positionwith respect to drive unit 14.

Still another alternate embodiment is shown as snowmobile 132 in FIG. 5wherein a pair of laterally spaced skis 134 and 136 having essentiallyplanar bottom surfaces 137 are coupled to platform 138 throughvertically acting spring suspension assemblies, not shown. Provision ismade for attaching main frame 12 to platform 138 by means of appropriatestuds, in like manner to that shown in snowmobile l0. Propulsion powerfor snowmobile 132 is derived from a motor driven ducted air propellerassembly 140 mounted to the rear of platform 138.

In operation, an occupant takes a position on seat 46 and places hisfeet on either side of platform 21 while grasping handlebars 98. As thesnowmobile is operated on level terrain and while not executing anyturns, seat 46 is most comfortable when ridden in a substantially levelposition. As the vehicle enters a turn, occupant leans in direction ofturn, as shown in FIGS. 2 and 5, so that the resultant of gravitationaland centrifugal force pushes his body down toward seat 46, as alsosteering ski 16 tilts laterally to dig into surface. On rough or hillyterrain, occupant can lean uphill as shown in FIG. 1 in order to adjusthis center of gravity to a position most favorable for negotiating theterrain.

The banking capability and additional spring suspension of the vehiclemain frame member 12, in conjunction with front steering assembly 94provide, in a simple design configuration, maneuverability, ridingcomfort, and control superior to that which can be obtained with moreconventional vehicles.

What is claimed is:

1. A snow vehicle comprising:

a main body member for supporting at least one rider;

first snow engaging means comprising a substantially planar lowersurface for supporting said snow vehicle by planar engagement withterrain;

propulsion means supported on said first snow engaging means for drivingsaid snow vehicle;

second snow engaging means including a substantially planar, elongated,lower surface for supporting a portion of the weight of said main bodymember, the total width of said lower planar surface being substantiallyless than the side edge to side edge width of said lower planarsurface'of said first snow engaging means;

pivotal mounting means for supporting said main body member on saidfirst snow engaging means for pivotal movement about a pivotallyinterconnected axis generally parallel to the longitudinal axis of saidsnow vehicle;

steering means mounted on said main body member and including meansinterconnecting said second snow engaging means to said main body memberfor rotating said second snow engaging means about a substantiallyvertical axis and about said pivotally interconnected axis;

control means comprising a reference platform including first and secondfoot engaging surfaces sup ported by said first snow engaging means onopposite sides of said main body member and including means forsupporting and maintaining said main body member and said lower surfaceof said second snow engaging means at a desired inclination with respectto said lower surface of said first snow engaging means and the terrainunder the snow vehicle,

whereby a rider mounted on said main body member may apply adifferential force to said first and second foot engaging surfaces withrespect to said main body member and causes said main body member, saidsteering means and said second snow engaging means to tilt with respectto said first snow engaging means and terrain.

2. A snow vehicle as set forth in claim 1 wherein said first snowengaging means comprises a single, continuously movable, wide trackdriven by said propulsion means.

3. A snow vehicle as set forth in claim 1 wherein said first snowengaging means comprises a pair of laterally spaced skis, said secondsnow engaging means comprises a single ski and said propulsion meanscomprises an air propeller drive unit.

4. A snow vehicle as set forth in claim 1 wherein said main body membercomprises at least one elastic member for completely constraining up anddown and pitching motion of said main body member with respect to saidsnow engaging means.

5. A snow vehicle as set forth in claim 1 further comprising lockingmeans for selectively interlocking said main body member and said firstsnow engaging means wherein said pivotal movement of said main bodymember about an axis generally parallel to the longitudinal vehicle axisis prevented.

6. A snow vehicle as set forth in claim 1 wherein said first snowengaging means comprises a continuously movable pair of laterally spacedtracks driven by said propulsion means.

7. A snow vehicle as set forth in claim 6 wherein said second snowengaging means comprises a single ski.

